Field of the Invention
The present invention relates to a semiconductor device, and in particular to a high-voltage semiconductor device.
Description of the Related Art
High-voltage semiconductor devices are applied to integrated circuits with high-voltage and high power. Traditional high-voltage semiconductor devices, such as a vertically diffused metal oxide semiconductor (VDMOS) or a laterally diffused metal oxide semiconductor (LDMOS), are mainly used for devices operated under at least 18 volts or higher. The advantages of high-voltage device technology include cost effectiveness and process compatibility, and this is why High-voltage device technology has been widely used in display driver IC devices, power supply devices, and such fields as power management, communications, automatics, and industrial control.
A high-voltage semiconductor device includes a high-voltage unit, a low-voltage unit and a level-shift unit disposed between the high-voltage unit and the low-voltage unit. The level-shift unit reduces voltage from the high-voltage unit, and reduced voltage is provided to the low-voltage unit. The level-shift unit also raises voltage from the low-voltage unit, and the raised voltage is provided to the high-voltage unit. However, a signal being transmitted from the low-voltage unit to the high-voltage unit without going through the level-shift unit occurs in conventional high-voltage semiconductor devices, which results in current leakage.
Therefore, it is necessary to develop a new high-voltage semiconductor device that can solve or improve the problems described above.